Plastic light diffuser and collimator



A. SCHRAGE E AL PLASTIC LIGHT DIFFUSER AND COLLIMATOR 'Fild Aug. 24, 1965 ALBERT SCHRAGE KARL F. KOCH INVENTORS fi/i yam,

Oct. 17, 1967 United States Patent y 3,348,039 PLASTIC LIGHT DIFFUSER AND COLLIMATGR Albert Schrage, East Orange, and Karl F. Koch, Berkeley Heights, NJ., assignors to Rexall Drug and Chemical Company, Los Angeles, Calif., a corporation of Delaware Filed Aug. 24, 1965, Ser. No. 482,048 1 Claim. (Cl. 24051.11)

ABSTRACT OF THE DISCLOSURE provides a protective covering for the bulb. I

This invention relates to a device for difiu'sing beams of light emanating from a light source, and in particular, to a plastic net-like sleeve'which diffuses and collimates the light of a fluorescent light bulb.

Light diffusers and collimators are widely known in the art. Commercially available light diffusers usually con sist of transluscent plastic shields attached to light fixtures so as to cause a divergence or scattering of the light beams emanating from the light source or bulb. This scattering of the light beams will effectively reduce the glare of the light bulb. However, there is a significant loss in available lumens or candle power resulting from light absorption by the transluscent plastic shield.

Collimators are used to control the direction of light beams emanating from a light bulb; generally causing the light beams to travel in confined parallel paths. When applied to fluorescent lighting fixtures, collimators take the form of deep grilles providing rectangular or square openings or perforations. Generally, the depth of the grille determines the degree of light beam collimation. This, in eflFect, channels the light beams directly onto the object or area to be illuminated and eliminates glare at any angle appreciably remote from the area being illuminated. A disadvantage of this particular type of collimator lies in its expensive construction, since they are usually formed of sheet metal, requiring accurate dimensioning for installation into the lighting fixtures.

The diffusing and collimating device according to the present invention overcomes the foregoing problems and disadvantages encountered in the prior art by providing an inexpensive plastic sleeve adapted to be positioned over a fluorescent lighting bulb. The device will effectively eliminate light glare, diffuse and collimate light beams emanating from the fluorescent lighting bulb, without an appreciable loss of the lighting intensity.

A further and surprising advantageous use of the novel diffusing and collimating device of this invention lies in that it may be utilized as an inexpensive packing and protector for the fluorescent bulb during storage and in transit.

In essence, the unique and advantageous diffusing and collimating device comprises a plurality of foam molded plastic rings which are interconnected by a plurality of transverse integrally molded strand members to thereby form a net-like sleeve adapted tobe positioned over a tubular flurorescent lighting bulb. The degree of ditfusion or collimation of the light beams emanating from the light bulb and passing through the openings in the net-like plastic sleeve is in direct proportion to the cross-sectional thickness of the plastic rings and strands, and in inverse proportion to the size of the openings therebetween.

3,348,039 Patented Oct. 17, 1967 Accordingly, it is an object of this invention to provide a novel and simple combined dilfusing and collimating device for light beams.

It is another object of this invention to provide an improved combined difliusing and collimating device consisting entirely of foam molded plastic construction.

A more particular object of this invention is to provide an inexpensive foam molded plastic combined diffusing and collimating device adapted to form a sleeveabout a tubular fluorescent bulb to form a protective covering therefor. i

The manner in which these and other objects and advantages of this invention will be attained will become apparent from the following detailed description and drawings, in which: i

FIGURE 1 is a perspective view of the device according to this invention assembled with a fluorescent'lighting bulb,

FIGURE 2 is an enlarged fragmentary portion of the device according to this invention,

FIGURE 3 is a partially schematic view of the device according to this invention,

FIGURE 4 is a further schematic view similar to'that of FIGURE 3, a

a lighting fixture, and

FIGURE 5 is a perspective view of the'device according to this invention shown installed in a presently known FIGURE 6 is a perspective view of the device according to this invention assembled with a fluorescent lighting bulb in the form of a torus.

Referring now in detail to the drawings, FIGURE 1 shows a bulb and light diffuser sleeve assembly 10. A cylindrical or tubular fluorescent light bulb 11 is covered over substantially its entire length by a sleeve 12. The sleeve 12 is of a mesh-like or net construction having a series of parallel spaced strand or ring member 13 surrounding the bulb 11. The ring members 13 are interconnected by a multiplicity of strands 14 which extend parallel to the axis of the bulb 11.

The ring members 13 and strands 14 form the net-like sleeve 12 so as to define a plurality of substantially rectangular openings 15 therein, as shown in FIGURE 2. The sleeve 12 is of an integrally molded construction, formed generally from a foam molded thermoplastic material. A thermoplastic material which would be particularly suitable for this particular application would be transluscent polystyrene.

The advantageous light diffusing and collimating effect of the sleeve 12 is clearly illustrated in FIGURE 3 and FIGURE 4 of the drawings. FIGURE 3 shows the light beams B being ditfused by the ring members 13 and strands 14 as the beams pass through openings 15. A major proportion of the light beams is directed straight through the openings 15 normal to the cylindrical surface of the bulb 11. This, in effect, will largely eliminate the glare encountered from fluorescent light bulbs. Since the sleeve 12 is of a generally transluscent material, there is only a relatively insignificant loss of lumen or candle power generated by the light bulb.

FIGURE 4 shows an assembly 10 substantially identical to that shown in FIGURE 3, with the only distinction being that the spacing between adjacent ring members 13 and strands 14 is shown to be somewhat larger. This will result in openings creased and thereby effect the diliusion of light beams B as a direct function of the dimensions of openings 15.

The entire bulb and sleeve assembly may be easily and simply instaHed in a standard fluorescent lighting fixture 16 as shown in FIGURE 5, generally used in oflices and other commercial structures. Presently available lighting fixtures may be easily adapted to the instant invention,

15 being proportionately in Another advantageous application of the novel net-like sleeve 12 is with respect to torus-shaped tubular fluorescent bulbs 17 as illustrated in FIGURE 6; This is due to the inherently resilient nature of the thermoplastic material of the sleeve 12, permitting its distortion into varied configurations as desired. The sleeve 12 may be furnished separately or as an assemblywith the bulb 11 or 17.-When furnished in an assembled condition, the sleeve 12 provides advantageously, a protective covering or packing for the fragile bulb. This eliminates the need for extensive and costly packings tor the bulbs during shipping and storage. Danger of bulb breakage in the event of accidental dropping thereof is also greatly obviated.v

The plastic sleeve 12 may also be impregnated with a coloring agent, whereby pleasant decorative eifects may be obtained by the light beams emanating from the bulbs From the foregoing, it quite clearly appears that the present invention provides an inexpensive device for collimat-ing and diffusing light emanating from a; fluorescent bulb, whereby costly grilles and diifuser plates are completely obviated.

obviously subject to variations and modifications without departing from itsbroader aspects;

What is claimed is:

In combination, a cylindricallighting tubesand av device for diffusing and collimating beams of light emanating from said tube; said device comprising a plurality of resilient thermoplastic ring members encompassing the periphery of said tube in parallel'spaced relationship, and a plurality of thermoplastic strand members integrally molded with and transversely interconnecting said ring members, said strand members extending substantially parallel to the longitudinal axis of said tube, said ring and strand members forming a vnet-like sleeve contacting:

and completely surrounding said tube and'having a multiplicity of generally rectangular openings therein which protects said tube during storage and-in transit.

References Cited V UNITED STATES PATENTS 7 7 2,391,325 12/1945 Maurette 240-5111 2,551,710 5/1951 Slaughter 2405l-.-11; 2,601,034 6/1952 Lee a 240108 2,740,216 4/l956 'Lieber-man 240-108 2,749,435 6/ 6 Appleton T 240-102 2,837,632 6/1958 Lipscomb 240-4639 73,169,710 2/1965 Lipscomb 240'46.'39

NORTON ANSHER, Primary Examiner.

RICHARD M. SHEER, Assistant Examiner; 

